Treatment of sewage.



T. K. IRWIN.

TREATMENT OF SEWAGE.

APPLICATION FILED AUG.16,1913.

1,083,888 Patented Jan. 6, 1914.

4 SHEETS-QHEET 1.

T. K. IRWIN. TREATMENT OF SEWAGE. APPLICATION FILED AUG.16, 1913.

Patented Jan. 6, 1-914.

4 SHEETS-SHEET Z.

Wrwss e5 T. K. IRWIN.

TREATMENT OF SEWAGE.

APPLICATION FILED AUG 16, 1913.

Patented J an. 6, 1914.

4 SHEETS-SHEET 3.

Aag

T. K. IRWIN.

TREATMENT OF SEWAGE.

APPLICATION FILEDAUG.1G,1913.

Patented Jan. 6, 1914 4 SHEETS-$113111 4.

THOMAS KEMPLAY IRWIN, OF LONDON, ENGLAND.

TREATMENT or SEWAGE.

Specification of Letters Patent. I

Patented. J an. 6, 1914.

Application filed August 16, 1913. Serial No. 785,078.

To all whom it may concern:

Be it known that I, THOMAS KEMPLAY IRWIN, a subject of His Majesty the King of England, residing at 5 London WVall Buildings, in the city and county of London, Kingdom of England, have invented certain new and useful Improvements Relating to I may be collected therefrom and utilized.

Now according to the present invention the whole process is carried out in a continuous mechanical manner and preferably with the use of the apparatus hereinafter described.

- In the process above referred to the separation of the solids from the liquid portion of the sludge takes place during fermentation, and the special feature of the said process is in the fact that almost all the solids are raised to the surface, in contradistinction to other processes wherein the greater portion of the solids is precipitated to the bottom. Advantage is taken of this special feature to deal with the fermented matter as hereinafter described.

In order thatmy invention may be more fully understood I will hereinafter describe' the same with reference to the accompanying drawings in which Figure 1 is a plan view illustrating one suitable and convenient arrangement of the apparatus; Fig. 2 is a longitudinal sectional elevation thereof; Fig. 3 is a transverse sectional elevation. Fig. 4 is a diagrammatic longitudinal section of one form of drier. Fig. is a cross section thereof. Fig. 6 is a section of the sludge grid pit; and Fig. 7 is a plan thereof.

For use in carrying out this process I employ (A) apparatus for measuring and mixing the sludge and ferment; (B) apparatus for-heating the mixture to the desired temperature; (C) receptacles in which the process of fermentation and separation may take place; (D) means for p'artly de-watering the fermented material; and (E) means for drymg the de-watered material and reducing it to a suitable powdered condition.

,As shown the improved apparatus comprises a sludge tank such as 4 from which the sludge is led by way of inlet troughs a to a sludge grid pit I) having grids or bars I) through which the sludge passes into a trough b the large matter, intercepted, being collected at 6 The sludge is then pumped, by means of a pump f by way of pipe f together with a supply of yeast from the yeast tank and mixer e and pipe 6 in fixed proportions, to the sludge heater (1. A conveyer c is provided to convey the sludge refuse collected on the part b of the grid pit b to the furnace 0 of the heater (Z as shown. The sludge conveyed to the vessel or heater d is heated through contact with suitably disposed heating surfaces and thereby raised to the temperature most suitable for fermentation, which experience shows to be about 80 Fahr. The vessel or heater d is preferably as shown elevated so that the heated fermenting mixture of sludge and yeast will flow therefrom by gravity to the fermenting receptacles h by Way of the pipe h and the sludge and yeast distributing trough g. The receptacles h are preferably in the form of a plurality of elongated troughs arranged side by side asshown and they are constructed of such cross-sectional area and length that a continuous flow of the mixture over the regulating sills g and through them may be maintained, at such a speed as will'insure that whereas the Warm mixture of sludge and ferment is constantly entering at one end, from the distributing trough g, a completely fermented and separated product Will flow 0d at the other end into the receiver-trough 2'. ,Practical tests indicate that the period of fermentation is from 18 to 24 hours, and, therefore, the time for the passage of the mixture throi'igh these tanks or troughs it must be at least 18 hours. To insure satisfactory separation, this period should always be as long as is practicable and economical. As hereinbe fore mentioned the solid portion of the sludge after fermentation, rises to the surface and floats, in effect, upon the liquid portion or eliluent.

Means for the constant removal of the risen fermented material from the outlet end of the troughs h is provided, the mechanism such .as the conveyers 25 for this purpose being 1 arranged to move along the troughs at the same rate as the mixture in them. In this .manner no disturbance is created, and no interference with the process of fermentation and separation occurs. ture of the mixture in the troughs is maintained by means of tubes or ductsp under the troughs h and through which hot air or gases or steam may be passed, its passage being regulated by dampers 305.

At the end of'the fermenting troughs h are provided eiiluent filter beds 70 which connect with a common eliluent receiver trough j into which the efiluent passes. The fermented sludge passes over outfall sills y to the aforesaid trough i from which it is pumped by means of a'pump m and pipes at to a suitable form of drier n, hereinafter described. I i

The fermented efiluentportion of i the sludge removed from the trough 7" contains about 80% of water and a considerable percentage of this is now eliminated by means of centritugalmachines Z the cages ofwhich are constructed with an annular chamber to carry suitable filtering material and are also provided with means for the rapid removal and replacement of the s'aid material. In these machines the separation of the solids from the. greater part of the remaininglliquid or eflluent is effected. They are further equipped with mechanism for the continuous or periodic removal of the deposited solids. The effluent from these machines Z may be again subjected to furapparatus, to introduce into the effluent, as.

ther filtration or allowed to flow away. The

deposited solids, after removal from the centrifugal machines are conveyed to a suitable apparatus for drying and pulverizing them. In the condition in which the solids leave the said centrifugal machines Z and enter .the drying apparatusthey are very gummy, a close in texture, and extremely tenacious andare consequently difficult to dry.

=Precipitation of the divided organic and nitrogenousmatter in the eliluent is facilitated and its capture in the hydro-extractor maehines Z is insured by-the addition of it passes away from the fermenting troughs h, lime,.alum, or other suitableprecipitating medium. Further in order-to prevent theescnpe of volatile combinations of nitrogen, provision is made for the-admixture with the sludge, either before or after fermentation, of a chemical (such as superf phosphate) which will retain them through and after the dryingprocess. I I The essential feature of the drier, one

form of which is shownin Figs 4 and 5, is,

therefore, means for breaking up the enter- The tempera-' ing solids into small particles so that they may come into intimate contact with hot air and gases and are this rapidly and economically dried. This is effected in a horizontal approximately cylindrical chamber n in the lower part of which is a rapidlyrotating shaft a, fitted with blades M, which receive the entering material as it falls from'the inlet 91 break it up, and project it into. all i parts of the chamber, catching it again as it falls and repeating the action continuously during the progress of thematerial along the chamber. Suitable slowly rotating scrapers n may be fitted in the upper part. I

of thech mber. I I I I Hot air or gas is passed around and through the drierchamberand the moisture from the drying material is carried off, with be readily traced as the flow of fresh sludge is shown by arrows 1; the-mixture of sludge and yeast to and from the heater (Z by arrows 2; the fermented sludge by arrows 3; the yeast by arrows l hot air by arrows 5; and the eflluent by arrows 6.

The working parts of the whole apparatus 'are runfrom a common motor 14 which also drives a hot air exhaust fan 9 as shown.

hat I claim and desire tosecureby Lettei s Patent of the United States is 1 1. The continuous process forthe treatment of sewage, which consists in first mixing yeast with the sludge, applying heat to the mixture and then delivering thexmixture to a suitable receptacle to cause a separation of the sludge and efiluent by fermentation.

2. The continuous process for the treatment of sewage, which consists in first mixing yeast with the sludge, applying heat to the mixture, delivering the mixture to a suitable receptacle to'cause a separation of the sludge and efiluent by fermentation and de-watering the effluent.

3. The continuousprocess for the treatment of sewage, which consists in first mixing yeast with the sludge, applying heat to the mixture,delivering the mixture to a suitable receptacle to cause sen'ration of the sludge and eflluent by fern" station, drying the de-watered material,r reducing the latter to a powder, I I

4. The continuous process for the treatment of sewage, which consists in first mixing yeast with the sludge, applyingflheat to the mixture, delivering the mixture to a specification in thepresence of two subscribsuiiable receptaclg ilrl1 W%1ih fengenitiziztion ing Witnesses; v an separation 0 t e su gean e uent takes place, de-Watering the efiiuent in a S M L Y 5 centrifugal machine, and drying the de- Witnesses:

Watered material. Tues. K. LOCKINGTON,

In testimony whereof I-have signed this FRANK BLAKEY.

00p! o! thh patent may he obtained (or five cefits eaoh, addrenlng the (iomminloner of Patents.

' I Washington, D. G." I 

